fix(lib): deprecate OnFormUpdate hook

If you patch your form and update a few values, this hook will be called multiple times: 1 time for each updated value. Which is not ideal.

Also has a bug here #127

And I've given more details here: #86 (comment)

README.md

@@ -538,7 +538,7 @@ export class CrewMemberComponent extends NgxSubFormComponent<CrewMember> {
 
 **Hooks**
 
-- `onFormUpdate`: Allows you to react whenever the form is being modified. Instead of subscribing to `this.formGroup.valueChanges` or `this.formControls.someProp.valueChanges` you will not have to deal with anything asynchronous nor have to worry about subscriptions and memory leaks. Just implement the method `onFormUpdate(formUpdate: FormUpdate<FormInterface>): void` and if you need to know which property changed do a check like the following: `if (formUpdate.yourProperty) {}`. Be aware that this method will be called only when there are either local changes to the form or changes coming from subforms. If the parent `setValue` or `patchValue` this method won't be triggered
+- `onFormUpdate` [**_deprecated_**]: Allows you to react whenever the form is being modified. Instead of subscribing to `this.formGroup.valueChanges` or `this.formControls.someProp.valueChanges` you will not have to deal with anything asynchronous nor have to worry about subscriptions and memory leaks. Just implement the method `onFormUpdate(formUpdate: FormUpdate<FormInterface>): void` and if you need to know which property changed do a check like the following: `if (formUpdate.yourProperty) {}`. Be aware that this method will be called only when there are either local changes to the form or changes coming from subforms. If the parent `setValue` or `patchValue` this method won't be triggered
 - `getFormGroupControlOptions`: Allows you to define control options for construction of the internal FormGroup. Use this to define form-level validators
 - `createFormArrayControl`: Allows you to create the `FormControl` of a given property of your form (to define validators for example). When you want to use this hook, implement the following interface `NgxFormWithArrayControls`
 - `handleEmissionRate`: Allows you to define a custom emission rate (top level or any sub level)

projects/ngx-sub-form/src/lib/ngx-sub-form.types.ts

@@ -2,7 +2,9 @@ import { FormControl, FormGroup, ValidationErrors } from '@angular/forms';
 import { Observable } from 'rxjs';
 import { ArrayPropertyKey, ArrayPropertyValue, Controls, FormUpdate } from './ngx-sub-form-utils';
 
+// @deprecated
 export interface OnFormUpdate<FormInterface> {
+  // @deprecated
   onFormUpdate?: (formUpdate: FormUpdate<FormInterface>) => void;
 }